Integration of unreal editor into game and shipment of source code for full modding

Development Programming & Scripting C++
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For my game i would like to integrade fully featured Editor right into game itself, in a single binary file, and launch in in a full screen mode right from main menu of game.
Since in-game editor is sort of in-game expirience (just like editor in Portal 2) and part of story i would like to restyle UI and re-brand it with in-game fictional name and simulation of fictional OS desktop with few more open source tools integrated in-game for creation of assets.
To allow users not just edit available assets, but freely change or create new gameplay features, assets, and even c++ classes, or total conversions that uses some game features, but fully changes everything about it (like we all was able to do in old Unreal Engine and Id tech engine days) i want to distribute custom made code of game and portions of Epic’s default sources needed to make game 100% moddable.
In addition to this i want to do built-in mod browser, with steam workshop and custom server mod browser, to make a fully integrated in-game user content development, distribution and usage.

And to make game future proof (you know, it feels so frustrating when afrer few years due of some changes in OS, some features became broken in game, or when some bugs remains or some not well designed features of game are so hardcoded so you cant improve it, and all of this can be avoided when source codes and assets are available), i want to distribute (as separate optional download) entire project and everything needed to improve, fix and recompile game in a future or if community would like to improve something about game.

Of course everything of this are planned to be done with lisence restrictions that basically means that any portions of code or assets are not allowed to be used outside of this game and without paying for it (and 5% goes to Epic as license terms says), and not allowed to gain any commercial profit of it. User have to agree with my own EULA that restricts any usage outside of game for those who does not own it, and user have to agree with additional EPIC EULA restrictions.

The reason i choose UE4 was access to full source code, which makes everything of above quite possible, i purchased UE4 license back in Aug 2014, and now, since UE4 is available for free i think all of this is even more possible than before since technically anyone can access UE4 Editor and source code on GitHub, so i dont see any reason for Epic to restrict access to customized UE4 editor and code included with game, under license terms that does not allow to use them for anything else but modding and improving game, and in case if they would use game sources and assets as base for their own commercial game (this what basically almost every dev of commercial afraid of, but i dont, and instead of restricting and fighting this i think i would be smarter just to force them to share profits), they should share profit with us and epic as well, or we would share part of this share with epic under additional license terms.

But my question is - am i allowed to do anything of this?
I dont see much of restrictions in license terms, but there are many things that seems questionable and not very clear.
Also, if current license terms restrict something of this, is it possible for indie devs, to avoid these restrictions, without paying big amount of money to Epic or without giving away insane royalties much bigger than 5% ?

I would like to hear public answer of epic representatives, and i think many people would like as well, because many of us wants our games to be fully 100% moddable and future proof, even commercial, but open-source, and legality of this is under question due of commercial nature of engine and many third party middleware included into it.

Also if you are not Epic, but support this idea of UE4 based games to be fully open for modification and even recompilation by end-users, please tell why you think epic should allow us doing this.

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This might be of interest: Does this mean that games cant be moddable? - General Discussion - Unreal Engine Forums

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Thanks, but that thread seems old and related to times when UE4 was not free for all. Back than such restrictions made sense to prevent people who have not paid for engine to get its features for free, but now when every kid around can download it for no cost and play with, would not it be great for epic to refresh the policy and EULA and allow editor and source to be shipped with games?
Also i dont see there answers to all of my questions, such as for example rebranding with fictional in-game name for editor, or anything about full code of game with customised engine. So i wish to hear some fresh words about this, that reflects current view of Epic on modding friendly game distribution.

Latest reply from Tim Does this mean that games cant be moddable? - General Discussion - Unreal Engine Forums aplies to old EULA that still requires membership, this clearly does not reflect most recent decision of making unreal engine free for all, that makes whole restriction absolete since anyone can access entire code and editor for free.

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I’m no lawyer, but based on the license under “Allowed forms of Distribution and Sublicensing”, part ‘a’:

That tells me you can… until you get to the end:

Which, given the editor would be considered a engine tool, tells me you wouldn’t be able to.

Part ‘b’ says you can distribute engine tools in source or object format to other licensees.

Semi-related: Based on a Twitter conversation I had earlier with @EpicJamesG, it won’t be made publically accessible and you still need an account, so people can’t just access UE4 now that it’s free.

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The short of it seems to be just the common sense of it: you can’t give away Epic’s property. However, its not that bad, your end user will need to sign and accept Epic’s EULA and read below:

Also, from the FAQ:

Can I ship a game that supports mods using the UE4 Editor or source?

Yes, and we have designed the UE4 Editor and launcher to accommodate this. We aim to build a unified UE4 development and modding community. Here is how this works: You’re free to release your game through any distribution channels of your choosing, however the UE4 Editor (including modified versions) and code may only be distributed through official Epic channels (e.g. the UE4 launcher for binaries, and GitHub for source), to users who have accepted the EULA.

Epic is in the process of opening up the UE4 launcher to developers who wish to ship games supporting mods using the UE4 Editor, and we think this is a great opportunity for games to inspire and benefit a rapidly-growing UE4 mod community. For an example of this process in action, see the Unreal Tournament tab within the UE4 launcher: it hosts the game, the editor, and a marketplace for user-created content. If you’re interested in early access, contact us.

**What kinds of products can I release with Unreal Engine 4?
**
You can release any product that is allowed by law, with the exception of gambling applications and certain safety-critical control systems described in the EULA. You can release games, demos, VR projects, architectural showcases, films and more.

The only parts of the Unreal Engine you can’t release to the general public are the source code and tools or modifications to them; these components may only be distributed to other licensees with access to the same version of the Unreal Engine.

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That was said after the drop of subscriptions. Ship your game as ever, but without the restricted parts (speak: Editor), ship your editor through the github organization tied to Epic, that is protected via registering/accepting the EULA here with Epic, or wait for the Marketplace solution to get viable (however that will look like (and what requires the registering as well)).

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So since things have changed quite a bit, has anyone followed up on this?

The closest I see is the VR Editor itself, is a sort of game. It is just missing power user features, like a simple browser window for Youtube!

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So i wonder what changed in this subject during last 7 years now when we ave UE5 ? Am i allowed now to ship game with editor (restricted to only work witing my game) and source code to save people from all sorts of discomfort and let them mod the game old fashion way (like you know when in UE1-2 times almost every game was shipped with unreal editor and was easily moddable without any extra requirements) ?

1 Like
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Yes, you can. I explain that here: Ship game with Unreal Editor like UEFN for full modding - #7 by bobby459001

And here’s where I explain how you can do that in UE4/5: Home - A Comprehensive Introduction to Unreal Engine Modding